Gas-air inspirator



Dec'. 1o, 1946. H fQ MECIER 2,412,348

v GAS-AIR vINSPIRA'I'OR Filed April .5, 1944 E INVENTon i A H. 0.MERCIER Patented Dec. 10, 1946i GAS-AIR IN SPIRATOR Harvey O. Mercier,East Orange, N. J., assignor to National Biscuit Company, New York, N.Y., a corporation of New Jersey Application April 3, 1944, Serial No.529,428

4 Claims.

My invention pertains to gas-air inspirators and has for its principalobject to improve the construction, accessibility, operation andeicienoy of inspirators generally and particularly of inspirators forsupplying a, combustible mixture of gaseous fuel and air to the burnersof baking ovens.

In the baking industry the air usually is laden with dust, such asflour, which clogs .the throats of inspirators and is deposited on thegas nozzles to such an extent that they must be cleaned at fairlyfrequent intervals. Heretofore, this has necessitated removing the gasnozzles and air shutters in order to clean the nozzle and throat. Thisrequired the services of an expert workman who could readjust thenozzles and shutters after they had been cleaned, so as to attain themost efficient gas-air mixture.

The length of time during which the inspirators can be used before theyrequire cleaning has been lengthened in some instances by taking in theair through a line screen or lter to remove much of the dust. This hasnot proven entirely satisfactory because much of the flour dust willpass through the finest practicable' screen and clog the throat, and thescreen itself soon becomes so clogged that sufficient air can not passthrough it. The disassemblingy cleaning and readjustment of aninspirator as heretofore used, not only requires a highly skilledworkman, but it takes from fifteen to thirty minutes to clean andreadjust each inspirator, and longer if a screen is used. Since a modernband oven may have up to two hundred or more inspirators and burners,the cost to clean and readjust the inspirators of one oven is aconsiderable amount, and may necessitate a shutdown of the oven if manyinspirators require cleaning at one time.

By means of the present invention, an unskilled workman can clean thenozzle and throat of an inspirator without changing its initialadjustment, and thereby restore it to its maximum efficiency in aboutone minute or less. Also, my invention makes it unnecessary to screenthe air thereby saving the cost of screens and their cleaning. However,in installations where the air is heavily dust laden, I may surround theair inlet with a, quick-removable screen which will prevent a large partof the dust from reaching the throat and nozzle.

In the accompanying drawing I have illustrated a preferred embodiment ofmy invention adapted to attain the above and other advantages.

Fig. 1 is a top View, partly in section, showing the gas nozzle inoperative position.

Fig. 2 is a side elevation, partly in section, showing the gas nozzleretracted for cleaning.

Fig. 3 is an end elevation, with the nozzle in section, looking in thedirection of the arrows 3--3 on Fig. 2. Y

The inspirator has a frame 5 with an integral body 6 at one end and anozzle guide 1 at the other. The body 6 is adapted to be secured at oneend to the gas mixture manifold or burner pipe 8, as by screw threads 9,and has the in-` spirator throat I0 formed within it. The throat I0preferably takes the form of a Venturi tube with its greatestconstriction adjacent the discharge point of the gas nozzle.

The gas nozzle I I has a sliding fit in both ends of the guide l, whichhas a bore I2 that is coaxial with the throat II'! and is large enoughto receive a collar I3 xed on the nozzle II. A spring I4 bearing on theguide plate I5 at one end and on the collar I3 at the other urges thenozzle to operative position toward the throat I Il, but permits it tobe retracted for cleaning as shown in Fig. 2. As appears from Fig. 1,the collar I3 limits forward movement of the nozzle.

At its rear end, the nozzle II is connected to the source of gas supplyby means such that it can be withdrawn from the throat I0, as by anelbow I6 and pipe Il, the latter being sufficiently flexible to permitthe nozzles being withdrawn. The pipe I'I, or connection leading to ithas a shut-01T valve and the usual pressure regulating valve forcontrolling the supply of gas to the nozzle.

At its forward end, the nozzle is restricted by a removable tip I8having an orice I9 from which a jet of gas is discharged intothe throatof the Venturi tube. The outside of the tip is curved as shown at 20 soas to approximate the curvature of the Venturi passage and give a freeflow-to the air that is inspirated around it. The tip I8 is removable sothat a tip having the correct size of orifice may be selected fordifferent qualities and pressures of gas and for different operatingconditions in the oven.

The outside of the nozzle II is screw threaded to receive the airshutter 2l and lock nut 22. The shutter is adjustable to control thewidth of the gap or air inlet 23. The width of the gap, within limits,determines the amount of air that is drawn in by the jet of gas into thethroat of the Venturi tube. kWhen the shutter 2| has been adjusted togive the best gas-air mixture, the nut 22 is tightened against it tohold it fixed and the air gap constant.

When dust, our or other material collects in the throatV It, on the tipla, or in the gap 23, so

as to affect the quality of the mixture, it is easily cleaned outwithout disturbing the setting of the shutter 2l and the air gap 23. AWorkman grasps the pipe Il or elbow I6 with one hand and pulls thenozzle back against the spring I4 to the position shown in Fig. 2. Inthe other hand he holds a cleaning tool which may be a scraper or brush,similar to a bottle cleaning brush, with which he cleans out the throatand brushes of the dust deposited on the tip I8 and shutter 2|. Thebrush or other cleaner may be connected to a suction hose so that allloosened dust is withdrawn. When the throat, tip and shutter are clean,the operator releases the pipe I'I and the spring I3 then snaps thenozzle back to operative position, restoring the gap 23 to its originalsize. The cleaning operation requires such a short time, usually notover one minute for each inspirator, and can Vbe done by unskilledlabor, so that the inspirators can always be kept in operation atmaximumeiciency. The cost of cleaning and time consumed are so little,that daily ro-utine cleaning of the inspirators is practicable and theaccumulation of dust never gets sufficient to Ycause seriousmal-functioning.

Usually the air need not be screened to remove dust, because the cost ofcleaning the inspirators will be less over an extended period than thecost of strainers or lte'rs and their upkeep. However, when the use ofan air screen is indicated, it may be a two part screen that is securedto the frame 5 Vand surrounds the guide I and body 6. It should bereadily detachable for cleaning. Or the screen may be inverted U-shapedso that it lits closely over the body 6 and guide 'i and against thesides of the frame 5. I have not illustrated a screen, because the useof screens over the air intakes of inspirators is well-known, 'and suchscreens are not part of my present invention.

If the. nozzle I I is pulled back for inspection or through accident, asin Fig. 2, the jet of gas from theori'ce I9 remains directed into thethroat of the venturi and mixes with air in quantity not toe `great tobe combustible, so' that the mixture will continue to burn at theburner, although not with maximum eilicieney. The flame will not beextinguished and will be 'restored to normal as soon as the spring i4returns the nozzle to operative position.

I have shown and described an inspirator that embodies my invention andit is to be considered as illustrative thereof and not a limitationthereon. The invention is capable of many variations, adaptations andmodiiications.

The collar lI3 limits the forward or inward movement of the nozzle andmay be adjustable on the nozzle instead of Xed, as illustrated. Theshutter v2| may be adjustable on the body 6 instead of on the nozzle.Another variation within the contemplation of my invention is to havethe nozzle I I xed and the shutter 2I on a sleeve that is slidable inthe body 6. VMany other changes in the inspirator, yet within `thevcontemplation of my invention will be suggested to those skilled in theart, and I claim all such that come within the scope of my claims or areequivalents'thereof.

What I claim is:

l. In a gas-air inspirator, the combination of a frame, a body integralwith the frame and having a passageway therethrough, a guide integralwith the frame and spaced from the body, 'said guide having a bore inalignment with said passageway, a nozzle slidably mounted in said boreand having its outlet adjacent to and discharging into one end of saidpassageway, a shutter adjustable on said nozzle adjacent said body tovary the air gap between said shutter and body, means whereby saidnozzle and shutter may be retracted Afrom said body by sliding in saidbore, and means for limiting return movement of the nozzlewherebyadjustment of the shutter with respect to the bodywill berestored when the nozzle is returned.

2. In a gas-air inspirator, the combination of a frame, a body and aguide on said frame in spaced apart relation, co-axial boresin saidbodyand guide, a nozzle 'extending through said guide and slidable in thebore therein, one end of said nozzle terminating in a gas discharge"oriiice ad'- jacent one end of said body bore, a shutter Vadjustable onsaid one 'end of 'said nozzle to', adjust the width of the gap betweenit andsaid body, means for locking the shutter in adjusted position onsaid nozzle and spaced Vfrom said guide, the'other end of said, nozzleAbeing connectedV to a gas supply, resilient means pressing said nozzleand shutter toward said body and lpermitting them to be retractedtherefrom, and mean-s limiting the movement of the nozzle and shuttertoward the body.

3. In a gas-air inspirator, the combination of a body and Vguide spacedapart and `liavin'ggooaxial bores therethrough, the bore in 'said bodyhaving a constricte'd throat, Ya nozzle slidable in the bore in saidvguide and having one end terminat'in'g inian oriiice adjacent theconstricted throat, a shutter adjustable on the nozzle to vary the widthof air gap between said shutter and body, means'for securing the shutterin adjusted position, said nozzle having a |stop limiting its movementtoward said body, asprng in the guide pressing the nozzle toward thebody but permitting said nozzle `and shutter to be retracted from thebody, the end of the nozzle opposite said orifice b'eing' 'adapted forconnection to ak gas supply.

4. In a' gas-air inspirator, the combination of a frame having" a bodyVanda guide spaced apart thereon, lsaid body .having a longitudinalbore, a nozzle in said guide having Aa discharge orice adjacent one endof the bore in the body, a shutter adjustable with respect tothedischarge end of the nozzle and body to var'y the space be- HARVEY o;MERCIER.

